选择题
2023 AMC 8 Problem 15: Walking Detour
Viswam walks half a mile to get to school each day. His route consists of 10 city blocks of equal length and he takes 1 minute to walk each block. Today, after walking 5 blocks, Viswam discovers he has to make a detour, walking 3 blocks of equal length instead of 1 block to reach the next corner. From the time he starts his detour, at what speed, in mph, must he walk in order to get to school at his usual time?
2023 AMC 8 第15题：步行绕行
Viswam 每天步行半英里去学校。他的路线由 10 个长度相等的城市街区组成，每个街区步行 1 分钟。今天，走了 5 个街区后，Viswam 发现他必须绕道，步行 3 个同等长度的街区而不是 1 个街区才能到达下一个拐角。从他开始绕道开始，他必须以什么速度（英里/小时）步行才能在平时的时间到达学校
A.
4
B.
4.2
C.
4.5
D.
4.8
E.
5